Multicenter Experience of Concomitant Use of Left Ventricular Assist Devices and Subcutaneous Implantable Cardioverter-Defibrillators

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: Data from a multicenter experience

BACKGROUND

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF). Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs with a lower risk of short- and long-term of device-related complications and infections.The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation.

METHODS

The study population included patients with a preexisting S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy.

RESULTS

The study population included 30 patients (25 male; median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population. Electromagnetic interference (EMI) occurred in 21 (70%) patients. The primary sensing vector was the one most significantly involved in determining EMI. Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector. The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks (IS) due to EMI. Six patients (20%) experienced appropriate shocks. No S-ICD extraction because of need for antitachycardia pacing, ineffective therapy or infection was reported.

CONCLUSIONS

Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS and undersensing in the post-operative period following LVAD implantation should be considered. Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

Subcutaneous implantable cardioverter-defibrillator noise following left ventricular assist device implantation

Background

The incidence and impact of noise in a subcutaneous implantable cardioverter defibrillator (S-ICD) after left ventricular assist device (LVAD) implantation is not well established.

Methods

We performed a retrospective study of patients implanted with LVAD and with a pre-existing S-ICD between January 2005 and December 2020 at the three Mayo Clinic centers (Minnesota, Arizona, and Florida).

Results

Of the 908 LVAD patients, a pre-existing S-ICD was present in 9 patients (mean age 49.1 ± 13.7 years, 66.7% males), 100% with Boston Scientific third-generation EMBLEM MRI S-ICD, 11% with HeartMate II (HM II), 44% with HeartMate 3 (HM 3), and 44% with HeartWare (HW) LVAD. The incidence of noise from LVAD-related electromagnetic interference (EMI) was 33% and was only seen with HM 3 LVAD. Multiple measures attempted to resolve noise, including using alternative S-ICD sensing vector, adjusting S-ICD time zone, and increasing LVAD pump speed, were unsuccessful, necessitating S-ICD device therapies to be turned off permanently.

Conclusions

The incidence of LVAD-related S-ICD noise is high in patients with concomitant LVAD and S-ICD with significant impact on device function. As conservative management failed to resolve the EMI, the S-ICDs had to be programmed off to avoid inappropriate shocks. This study highlights the importance of awareness of LVAD-SICD device interference and the need to improve S-ICD detection algorithms to eliminate noise.

Device-device interaction between cardiac implantable electronic devices and continuous-flow left ventricular assist devices

The current design of an innovative left ventricular assist device (LVAD) makes use of magnetic levitation technology, which enables the rotors of the device to be completely suspended by magnetic force, reducing friction and blood or plasma damage. However, this electromagnetic field can result in electromagnetic interference (EMI), which can interfere with proper functioning of another cardiac implantable electronic device (CIED) in its direct proximity. Approximately 80% of patients with an LVAD have a CIED, most frequently an implantable cardioverter-defibrillator (ICD). Several device-device interactions have been reported, including EMI-induced inappropriate shocks, inability to establish telemetry connection, EMI-induced premature battery depletion, undersensing by the device, and other CIED malfunctions. Unfortunately, additional procedures, including generator exchange, lead adjustment, and system extraction, are frequently required because of these interactions. In some circumstances, the additional procedure might be preventable or avoidable with appropriate solutions. In this article, we describe how EMI from the LVAD impacts the functionality of the CIED and provide possible management options, including manufacturer-specific information, for the current CIEDs (eg, transvenous and leadless pacemakers, transvenous and subcutaneous ICDs, and transvenous cardiac resynchronization therapy pacemakers and ICDs).

Approaches to Minimizing Periprocedural Complications During Subcutaneous Implantable Cardioverter-defibrillator Placement

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is the latest option among devices clinically available for the prevention of sudden cardiac death, with experience from previous trials and postmarketing studies supporting the feasibility and safety of this kind of system. The extracardiac positioning of the S-ICD obviates the need for transvenous leads, which translates into lower incidence rates of lead-related complications and systemic infections. This review will highlight the results of pertinent studies related to the perioperative management of S-ICDs and review potential approaches to minimizing the risk of complications such as hematoma at the pulse generator location, unsuccessful defibrillation due to suboptimal S-ICD lead and generator positioning, and postoperative pain. An extensive literature search using PubMed was conducted to identify relevant articles.

Electromagnetic interference from left ventricular assist devices in patients with subcutaneous implantable cardioverter-defibrillators

INTRODUCTION

Interactions of left ventricular assist devices (LVADs) with transvenous implantable cardioverter-defibrillator systems (ICDs) have been widely reported. However, less is known regarding the impact of electromagnetic interference (EMI) from LVADs on subcutaneous ICD function.

METHODS AND RESULTS

A comprehensive literature search was performed on PubMed, Cochrane central registry, and Google Scholar using the search terms "subcutaneous implantable cardioverter-defibrillator and left ventricular assist devices," "electromagnetic interference, LVAD, and subcutaneous ICD," "EMI and S-ICD," and "inappropriate shocks, LVAD, and ICD." Demographic and programming data were extracted from the reports and authors as needed. A total of seven cases of EMI in LVAD patients with subcutaneous ICD (S-ICD) devices were found. In addition three previously unreported cases from our center were included. All cases involved either a heartware ventricular assist device or HeartMate III LVAD with a pre-existing S-ICD. In all patients, both the primary and secondary vectors had inappropriate sensing due to EMI. Three patients were reprogramed to the alternate vector with appropriate sensing. The S-ICD was either inactivated or replaced with a transvenous device in six patients. A single patient was left sensing in the alternate vector. There were no reports of inability to interrogate S-ICD systems in patients with LVADs.

CONCLUSION

The risk of inappropriate shocks from LVADs should be considered in pre-existing patients with S-ICD, particularly when the heartware ventricular assist device or HeartMate III LVAD device is present. Reprogramming of the sensing vector can occasionally avoid this issue but often the S-ICD needs to be inactivated.

Evolution of extravascular implantable defibrillator technologies

The implantable cardioverter-defibrillator (ICD) has been successfully treating patients with lethal ventricular arrhythmias for decades. The main acute and chronic complications of this therapy modality are related to the use of a transvenous lead. An entirely extravascular ICD concept was developed over the last 20 years, with emergence of the subcutaneous ICD (S-ICD). This device was approved for clinical use seven years ago, and accumulating real-life experience confirms its safety and efficacy. The main limitations related to this system include the lack of pacing capabilities for bradycardia, tachycardia or resynchronization therapy, a large size, and relatively high energy requirements for effective defibrillation. This review article summarizes current knowledge and potential future developments of the extravascular ICD technologies.